Black Prison and Heavenly Sword Union. Yang Kai needs to crush the defenses of these two sects and then get the golden embodiment to devour their planets' vitality with the Heaven Devouring Battle Law. Once they are dead world, Ah Da can come and eat them. For all intents and purposes, it will be as if those two sects never existed because their cultivation stars would cease to exist without a trace. That would teach other sects the price of offending the Void Land.